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	/*
	* Copyright (c) 1997, 2009, Oracle and/or its affiliates. All rights reserved.
	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
	*
	* This code is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License version 2 only, as
	* published by the Free Software Foundation. Oracle designates this
	* particular file as subject to the "Classpath" exception as provided
	* by Oracle in the LICENSE file that accompanied this code.
	*
	* This code is distributed in the hope that it will be useful, but WITHOUT
	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
	* version 2 for more details (a copy is included in the LICENSE file that
	* accompanied this code).
	*
	* You should have received a copy of the GNU General Public License version
	* 2 along with this work; if not, write to the Free Software Foundation,
	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
	*
	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
	* or visit www.oracle.com if you need additional information or have any
	* questions.
	*/

	package com.sun.crypto.provider;

	import java.security.*;
	import java.security.spec.*;
	import javax.crypto.*;
	import javax.crypto.spec.*;
	import javax.crypto.BadPaddingException;

	/**
	* This class implements the DES algorithm in its various modes
	* (<code>ECB</code>, <code>CFB</code>, <code>OFB</code>, <code>CBC</code>,
	* <code>PCBC</code>) and padding schemes (<code>PKCS5Padding</code>,
	* <code>NoPadding</code>, <code>ISO10126Padding</code>).
	*
	* @author Gigi Ankeny
	* @author Jan Luehe
	* @see DESCrypt
	* @see CipherBlockChaining
	* @see ElectronicCodeBook
	* @see CipherFeedback
	* @see OutputFeedback
	*/

	public final class DESCipher extends CipherSpi {

	/*
	* internal CipherCore object which does the real work.
	*/
	private CipherCore core = null;

	/**
	* Creates an instance of DES cipher with default ECB mode and
	* PKCS5Padding.
	*/
	public DESCipher() {
	core = new CipherCore(new DESCrypt(), DESConstants.DES_BLOCK_SIZE);
	}

	/**
	* Sets the mode of this cipher.
	*
	* @param mode the cipher mode
	*
	* @exception NoSuchAlgorithmException if the requested cipher mode does
	* not exist
	*/
	protected void engineSetMode(String mode)
	throws NoSuchAlgorithmException {
	core.setMode(mode);
	}

	/**
	* Sets the padding mechanism of this cipher.
	*
	* @param paddingScheme the padding mechanism
	*
	* @exception NoSuchPaddingException if the requested padding mechanism
	* does not exist
	*/
	protected void engineSetPadding(String paddingScheme)
	throws NoSuchPaddingException {
	core.setPadding(paddingScheme);
	}

	/**
	* Returns the block size (in bytes).
	*
	* @return the block size (in bytes), or 0 if the underlying algorithm is
	* not a block cipher
	*/
	protected int engineGetBlockSize() {
	return DESConstants.DES_BLOCK_SIZE;
	}

	/**
	* Returns the length in bytes that an output buffer would need to be in
	* order to hold the result of the next <code>update</code> or
	* <code>doFinal</code> operation, given the input length
	* <code>inputLen</code> (in bytes).
	*
	* <p>This call takes into account any unprocessed (buffered) data from a
	* previous <code>update</code> call, and padding.
	*
	* <p>The actual output length of the next <code>update</code> or
	* <code>doFinal</code> call may be smaller than the length returned by
	* this method.
	*
	* @param inputLen the input length (in bytes)
	*
	* @return the required output buffer size (in bytes)
	*/
	protected int engineGetOutputSize(int inputLen) {
	return core.getOutputSize(inputLen);
	}

	/**
	* Returns the initialization vector (IV) in a new buffer.
	*
	* <p>This is useful in the case where a random IV has been created
	* (see <a href = "#init">init</a>),
	* or in the context of password-based encryption or
	* decryption, where the IV is derived from a user-provided password.
	*
	* @return the initialization vector in a new buffer, or null if the
	* underlying algorithm does not use an IV, or if the IV has not yet
	* been set.
	*/
	protected byte[] engineGetIV() {
	return core.getIV();
	}

	/**
	* Returns the parameters used with this cipher.
	*
	* <p>The returned parameters may be the same that were used to initialize
	* this cipher, or may contain the default set of parameters or a set of
	* randomly generated parameters used by the underlying cipher
	* implementation (provided that the underlying cipher implementation
	* uses a default set of parameters or creates new parameters if it needs
	* parameters but was not initialized with any).
	*
	* @return the parameters used with this cipher, or null if this cipher
	* does not use any parameters.
	*/
	protected AlgorithmParameters engineGetParameters() {
	return core.getParameters("DES");
	}

	/**
	* Initializes this cipher with a key and a source of randomness.
	*
	* <p>The cipher is initialized for one of the following four operations:
	* encryption, decryption, key wrapping or key unwrapping, depending on
	* the value of <code>opmode</code>.
	*
	* <p>If this cipher requires an initialization vector (IV), it will get
	* it from <code>random</code>.
	* This behaviour should only be used in encryption or key wrapping
	* mode, however.
	* When initializing a cipher that requires an IV for decryption or
	* key unwrapping, the IV
	* (same IV that was used for encryption or key wrapping) must be provided
	* explicitly as a
	* parameter, in order to get the correct result.
	*
	* <p>This method also cleans existing buffer and other related state
	* information.
	*
	* @param opmode the operation mode of this cipher (this is one of
	* the following:
	* <code>ENCRYPT_MODE</code>, <code>DECRYPT_MODE</code>,
	* <code>WRAP_MODE</code> or <code>UNWRAP_MODE</code>)
	* @param key the secret key
	* @param random the source of randomness
	*
	* @exception InvalidKeyException if the given key is inappropriate for
	* initializing this cipher
	*/
	protected void engineInit(int opmode, Key key, SecureRandom random)
	throws InvalidKeyException {
	core.init(opmode, key, random);
	}

	/**
	* Initializes this cipher with a key, a set of
	* algorithm parameters, and a source of randomness.
	*
	* <p>The cipher is initialized for one of the following four operations:
	* encryption, decryption, key wrapping or key unwrapping, depending on
	* the value of <code>opmode</code>.
	*
	* <p>If this cipher (including its underlying feedback or padding scheme)
	* requires any random bytes, it will get them from <code>random</code>.
	*
	* @param opmode the operation mode of this cipher (this is one of
	* the following:
	* <code>ENCRYPT_MODE</code>, <code>DECRYPT_MODE</code>,
	* <code>WRAP_MODE</code> or <code>UNWRAP_MODE</code>)
	* @param key the encryption key
	* @param params the algorithm parameters
	* @param random the source of randomness
	*
	* @exception InvalidKeyException if the given key is inappropriate for
	* initializing this cipher
	* @exception InvalidAlgorithmParameterException if the given algorithm
	* parameters are inappropriate for this cipher
	*/
	protected void engineInit(int opmode, Key key,
	AlgorithmParameterSpec params,
	SecureRandom random)
	throws InvalidKeyException, InvalidAlgorithmParameterException {
	core.init(opmode, key, params, random);
	}

	protected void engineInit(int opmode, Key key,
	AlgorithmParameters params,
	SecureRandom random)
	throws InvalidKeyException, InvalidAlgorithmParameterException {
	core.init(opmode, key, params, random);
	}

	/**
	* Continues a multiple-part encryption or decryption operation
	* (depending on how this cipher was initialized), processing another data
	* part.
	*
	* <p>The first <code>inputLen</code> bytes in the <code>input</code>
	* buffer, starting at <code>inputOffset</code>, are processed, and the
	* result is stored in a new buffer.
	*
	* @param input the input buffer
	* @param inputOffset the offset in <code>input</code> where the input
	* starts
	* @param inputLen the input length
	*
	* @return the new buffer with the result
	*
	* @exception IllegalStateException if this cipher is in a wrong state
	* (e.g., has not been initialized)
	*/
	protected byte[] engineUpdate(byte[] input, int inputOffset,
	int inputLen) {
	return core.update(input, inputOffset, inputLen);
	}

	/**
	* Continues a multiple-part encryption or decryption operation
	* (depending on how this cipher was initialized), processing another data
	* part.
	*
	* <p>The first <code>inputLen</code> bytes in the <code>input</code>
	* buffer, starting at <code>inputOffset</code>, are processed, and the
	* result is stored in the <code>output</code> buffer, starting at
	* <code>outputOffset</code>.
	*
	* @param input the input buffer
	* @param inputOffset the offset in <code>input</code> where the input
	* starts
	* @param inputLen the input length
	* @param output the buffer for the result
	* @param outputOffset the offset in <code>output</code> where the result
	* is stored
	*
	* @return the number of bytes stored in <code>output</code>
	*
	* @exception ShortBufferException if the given output buffer is too small
	* to hold the result
	*/
	protected int engineUpdate(byte[] input, int inputOffset, int inputLen,
	byte[] output, int outputOffset)
	throws ShortBufferException {
	return core.update(input, inputOffset, inputLen, output,
	outputOffset);
	}

	/**
	* Encrypts or decrypts data in a single-part operation,
	* or finishes a multiple-part operation.
	* The data is encrypted or decrypted, depending on how this cipher was
	* initialized.
	*
	* <p>The first <code>inputLen</code> bytes in the <code>input</code>
	* buffer, starting at <code>inputOffset</code>, and any input bytes that
	* may have been buffered during a previous <code>update</code> operation,
	* are processed, with padding (if requested) being applied.
	* The result is stored in a new buffer.
	*
	* <p>The cipher is reset to its initial state (uninitialized) after this
	* call.
	*
	* @param input the input buffer
	* @param inputOffset the offset in <code>input</code> where the input
	* starts
	* @param inputLen the input length
	*
	* @return the new buffer with the result
	*
	* @exception IllegalBlockSizeException if this cipher is a block cipher,
	* no padding has been requested (only in encryption mode), and the total
	* input length of the data processed by this cipher is not a multiple of
	* block size
	* @exception BadPaddingException if this cipher is in decryption mode,
	* and (un)padding has been requested, but the decrypted data is not
	* bounded by the appropriate padding bytes
	*/
	protected byte[] engineDoFinal(byte[] input, int inputOffset,
	int inputLen)
	throws IllegalBlockSizeException, BadPaddingException {
	return core.doFinal(input, inputOffset, inputLen);
	}

	/**
	* Encrypts or decrypts data in a single-part operation,
	* or finishes a multiple-part operation.
	* The data is encrypted or decrypted, depending on how this cipher was
	* initialized.
	*
	* <p>The first <code>inputLen</code> bytes in the <code>input</code>
	* buffer, starting at <code>inputOffset</code>, and any input bytes that
	* may have been buffered during a previous <code>update</code> operation,
	* are processed, with padding (if requested) being applied.
	* The result is stored in the <code>output</code> buffer, starting at
	* <code>outputOffset</code>.
	*
	* <p>The cipher is reset to its initial state (uninitialized) after this
	* call.
	*
	* @param input the input buffer
	* @param inputOffset the offset in <code>input</code> where the input
	* starts
	* @param inputLen the input length
	* @param output the buffer for the result
	* @param outputOffset the offset in <code>output</code> where the result
	* is stored
	*
	* @return the number of bytes stored in <code>output</code>
	*
	* @exception IllegalBlockSizeException if this cipher is a block cipher,
	* no padding has been requested (only in encryption mode), and the total
	* input length of the data processed by this cipher is not a multiple of
	* block size
	* @exception ShortBufferException if the given output buffer is too small
	* to hold the result
	* @exception BadPaddingException if this cipher is in decryption mode,
	* and (un)padding has been requested, but the decrypted data is not
	* bounded by the appropriate padding bytes
	*/
	protected int engineDoFinal(byte[] input, int inputOffset, int inputLen,
	byte[] output, int outputOffset)
	throws IllegalBlockSizeException, ShortBufferException,
	BadPaddingException {
	return core.doFinal(input, inputOffset, inputLen, output,
	outputOffset);
	}

	/**
	* Returns the key size of the given key object.
	*
	* @param key the key object.
	*
	* @return the key size of the given key object.
	*
	* @exception InvalidKeyException if <code>key</code> is invalid.
	*/
	protected int engineGetKeySize(Key key) throws InvalidKeyException {
	byte[] encoded = key.getEncoded();
	if (encoded.length != 8) {
	throw new InvalidKeyException("Invalid key length: " +
	encoded.length + " bytes");
	}
	return 56;
	}

	/**
	* Wrap a key.
	*
	* @param key the key to be wrapped.
	*
	* @return the wrapped key.
	*
	* @exception IllegalBlockSizeException if this cipher is a block
	* cipher, no padding has been requested, and the length of the
	* encoding of the key to be wrapped is not a
	* multiple of the block size.
	*
	* @exception InvalidKeyException if it is impossible or unsafe to
	* wrap the key with this cipher (e.g., a hardware protected key is
	* being passed to a software only cipher).
	*/
	protected byte[] engineWrap(Key key)
	throws IllegalBlockSizeException, InvalidKeyException {
	return core.wrap(key);
	}

	/**
	* Unwrap a previously wrapped key.
	*
	* @param wrappedKey the key to be unwrapped.
	*
	* @param wrappedKeyAlgorithm the algorithm the wrapped key is for.
	*
	* @param wrappedKeyType the type of the wrapped key.
	* This is one of <code>Cipher.SECRET_KEY</code>,
	* <code>Cipher.PRIVATE_KEY</code>, or <code>Cipher.PUBLIC_KEY</code>.
	*
	* @return the unwrapped key.
	*
	* @exception NoSuchAlgorithmException if no installed providers
	* can create keys of type <code>wrappedKeyType</code> for the
	* <code>wrappedKeyAlgorithm</code>.
	*
	* @exception InvalidKeyException if <code>wrappedKey</code> does not
	* represent a wrapped key of type <code>wrappedKeyType</code> for
	* the <code>wrappedKeyAlgorithm</code>.
	*/
	protected Key engineUnwrap(byte[] wrappedKey,
	String wrappedKeyAlgorithm,
	int wrappedKeyType)
	throws InvalidKeyException, NoSuchAlgorithmException {
	return core.unwrap(wrappedKey, wrappedKeyAlgorithm,
	wrappedKeyType);
	}
	}

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